Typically drone aircraft have been powered using power provided by an onboard battery. However, due to the limitation in the amount of energy able to be stored in a battery of a size and weight suitable for the drone aircraft, flight times of drone aircraft have been severely limited. In order to increase flight time, a gasoline engine may be utilized to take advantage of the higher energy density of gasoline. However, as compared to battery power, gasoline engines require an externally controlled throttle to provide power and cannot provide power as instantaneously. There is a lag between when engine throttle is increased and when full power corresponding to the increase engine throttle is delivered. To meet instantaneous power demand, a battery may be used in conjunction with the gasoline engine to allow the battery to bridge the gap in power during the throttle lag. However, there may be instances when battery power is unavailable or undesirable. For example, the battery in the hybrid battery-engine system may fail and it would be desirable to be able to operate the drone aircraft without reliance on battery power. For certain applications, the use of the battery is undesirable due to its added complexity, weight, and cost.